1. Field of the Invention
The present invention relates to printers, and more specifically to a rasterizing sub-system used in a printer.
2. Related Art
Printers are often used to print a specified content on medium such as paper. Typically, a printer receives a request from an external system such as a personal computer, and prints the content specified in the request. The content to be printed is generally specified by page description languages (PDL) such as Postscript (PS) and printer control language (PCL), as is well known in the relevant arts.
Printers often contain rasterizer sub-systems for generating a bit map representing the page content to be printed. The bit map is generally generated according to the PDL statements as is well known in the relevant arts. Rasterizer sub-systems often need to be implemented meeting several features. One feature is to minimize the usage of memory and/or processing requirements.
Another desirable feature that is to be supported by a rasterizer sub-system is half toning. Half toning in generally refers to obtaining a particular shade of a color by generating dots of varying color intensity very close to each other. For example, a printer may support only black and white (i.e., no printing) dots, and a grey color may be obtained by printing a number of black dots proportionate to the desired color intensity within a small area (often referred to as half-tone cell). As the human eye inherently ‘averages’ the colors in a close/small area, the area (in each cell) may be perceived to contain a grey shade.
What is therefore needed is a method and apparatus which supports rasterization to generate bit maps suitable for printing on a printer while meeting one or more requirements.